System and Method for Powering and Deploying an Electric Submersible Pump

ABSTRACT

A system for deploying and powering an electric submersible pump within a subterranean well. The system includes a tubing string having a wall forming a first conductive path, one end of which is connected to the electric submersible pump; and a second conductive path, wherein the first conductive path and the second conductive path form a circuit for supplying power to the electric submersible pump. A method for deploying and powering an electric submersible pump within a subterranean well is also provided.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/208,025, filed Aug. 21, 2015, entitled “System and Method forPowering and Deploying an Electric Submersible Pump,” the entirety ofwhich is incorporated by reference herein. This application is alsorelated to and claims the benefit of U.S. Provisional Application No.62/209,596, filed Aug. 25, 2015 (Attorney Docket No. 2015EM137),entitled, “System and Method for Powering and Deploying an ElectricSubmersible Pump,” the disclosure of which is incorporated by referencein its entirety.

FIELD

The present disclosure relates to systems and methods for deploying andpowering electric submersible pumps.

BACKGROUND

The utility of electric submersible pumps (ESPs) is sometimes limited byconventional deployment and retrieval methods. A conventional ESP may beinstalled with a tubing string, requiring a full rig to perform thework. Such installations can be costly, particularly in offshore andremote locations, frequently making ESP installations and retrievalseconomically prohibitive. As such, a desirable deployment method wouldavoid the need for a rig and allow the assembled ESP system to be“stripped” into the well through-tubing. Coiled-tubing and cabledeployed ESPs have been developed that meet these requirements, but theystill have limitations.

The most flexible commercially available coiled-tubing-deployed systememploys an internally-installed cable. The cable used is pumped into thecoiled tubing, with 10,000 feet the greatest length that vendors havebeen able to install. A three-phase, No. 2 AWG cable inside of 1¾″coiled tubing represents a typical application. The cable may or may notbe anchored inside the coiled tubing, and thermal expansion/contractioneffects may be a concern. As may be appreciated, thecable-in-coiled-tubing reel is quite heavy, and lifting operations canchallenge offshore cranes; certain platforms may require a support bargefor installation. The system cannot easily be spliced, which means theentire string can be lost if there is an issue. Spooling andstraightening of the reel can weaken or damage the cable and limitre-use.

Despite these advances, what is needed are improved systems and methodsfor deploying and powering an electric submersible pump within asubterranean well, which enable deployment at depths greater than about10,000 feet.

SUMMARY

In one aspect, disclosed herein is a system for deploying and poweringan electric submersible pump within a subterranean well. The systemincludes a tubing string having a wall forming a first conductive path,one end of which is connected to the electric submersible pump; and asecond conductive path, wherein the first conductive path and the secondconductive path form a circuit for supplying power to the electricsubmersible pump.

In some embodiments, the subterranean well comprises a casing andproduction tubing positioned within the casing, the interior surface ofthe casing and the exterior surface of the production tubing defining anannular space.

In some embodiments, the production tubing forms the second conductivepath.

In some embodiments, the tubing string includes a conductive metallicmaterial, the outer surface of which is coated with an insulating,non-conductive material.

In some embodiments, the subterranean well includes a casing which formsan annulus with the tubing string, the casing forming the secondconductive path.

In some embodiments, the electric submersible pump includes an ESPmotor, the ESP motor selected from a two-phase AC ESP motor or a DC ESPmotor.

In some embodiments, the system further includes a downhole DC-to-ACinverter for powering a three-phase AC ESP motor.

In some embodiments, the system further includes a third conductive pathto power a three-phase AC ESP motor.

In some embodiments, the electric submersible pump includes at least onesensor and power is transmitted through the system to power the electricsubmersible pump.

In some embodiments, a signal is impressed upon the power transmitted toprovide a communications link between the electric submersible pumpsensors and surface systems.

In another aspect, disclosed herein is a method for deploying andpowering an electric submersible pump within a subterranean well. Themethod includes providing a tubing string having a wall forming a firstconductive path, connecting the tubing string to the electricsubmersible pump; positioning the tubing string and electric submersiblepump within the subterranean well; providing a second conductive path;and forming a circuit for supplying power to the electric submersiblepump, the circuit comprising the first conductive path and the secondconductive path.

In some embodiments, the subterranean well comprises a casing andproduction tubing positioned within the casing, the interior surface ofthe casing and the exterior surface of the production tubing defining anannular space.

In some embodiments, the production tubing forms the second conductivepath.

In some embodiments, the tubing string includes a conductive metallicmaterial, the outer surface of which is coated with an insulating,non-conductive material.

In some embodiments, the subterranean well includes a casing which formsan annulus with the tubing string, the casing forming the secondconductive path.

In some embodiments, the electric submersible pump includes an ESPmotor, the ESP motor selected from a two-phase AC ESP motor or a DC ESPmotor.

In some embodiments, the method further includes a downhole DC-to-ACinverter for powering a three-phase AC ESP motor.

In some embodiments, the method further includes a third conductive pathto power a three-phase AC ESP motor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 presents a schematic view of a conventional system for deployingand powering an electric submersible pump within a subterranean well.

FIG. 2 presents a schematic view of yet another illustrative,nonexclusive example of a system for deploying and powering an electricsubmersible pump within a subterranean well, according to the presentdisclosure.

FIG. 3 presents another method for deploying and powering an electricsubmersible pump within a subterranean well, according to the presentdisclosure.

DETAILED DESCRIPTION

In FIGS. 1-3, like numerals denote like, or similar, structures and/orfeatures; and each of the illustrated structures and/or features may notbe discussed in detail herein with reference to the figures. Similarly,each structure and/or feature may not be explicitly labeled in thefigures; and any structure and/or feature that is discussed herein withreference to the figures may be utilized with any other structure and/orfeature without departing from the scope of the present disclosure.

In general, structures and/or features that are, or are likely to be,included in a given embodiment are indicated in solid lines in thefigures, while optional structures and/or features are indicated inbroken lines. However, a given embodiment is not required to include allstructures and/or features that are illustrated in solid lines therein,and any suitable number of such structures and/or features may beomitted from a given embodiment without departing from the scope of thepresent disclosure.

FIGS. 2-3 provide illustrative, non-exclusive examples of methods andsystems for deploying and powering electric submersible pumps withinsubterranean wells, according to the present disclosure, together withelements that may include, be associated with, be operatively attachedto, and/or utilize such a method or system.

Although the approach disclosed herein can be applied to a variety ofsubterranean well designs and operations, the present description willprimarily be directed to for deploying and powering electric submersiblepumps within subterranean wells.

FIG. 1 presents, for illustrative purposes, a schematic view of aconventional system 10 for deploying and powering an electricsubmersible pump 12 within a subterranean well 14. As shown, thesubterranean well 14 includes a casing 16 and production tubing 18positioned within the casing 16. The interior surface 20 of the casing16 and the exterior surface 22 of the production tubing 18 serve todefine an annular space A.

The system 10 includes a tubing string 24, which may be formed from acoiled tubing 26. Tubing string 24 includes a wall 28 forming a hollowinterior 30. One end 32 of the tubing string 24 is connected to theelectric submersible pump 12.

To provide power to electric submersible pump 12, a conventional cable34 is installed within the hollow interior 30 of tubing string 24. Cable34 may be provided with three conductors to power a three phase ESPmotor 13 of the electric submersible pump 12. Should a two phase ESPmotor 13 be employed, cable 34 may be provided with two or threeconductors for supplying power to the ESP motor 13.

Prior to installation of tubing string 24 within the well, theconventional cable 34 may be installed within the hollow interior 30 oftubing string 24 by pumping the conventional cable 34 into the tubingstring 24, which may be in the form of a coiled tubing 26. This methodof installation is limited to about 10,000 feet in length, the greatestlength that suppliers have been able to install. As may be appreciatedby those skilled in the art, an installation exceeding this limitationwould then require a full rig. This can prove costly, particularly inoffshore and remote locations, sometimes making electric submersiblepump installations and retrievals economically prohibitive.

In operation, produced fluids enter the well 14 at perforations 36, passthrough the production tubing 18, enter inlet 38 of electric submersiblepump 12, and are discharged at outlet 40 into the annulus B formed bythe inner surface 42 of production tubing 18 and the exterior surface 29of wall 28 of tubing string 24, exiting at the surface. Seal 44 isinstalled to direct produced fluids to inlet 38 of electric submersiblepump 12.

Referring now to FIG. 2, a schematic view of an illustrative,nonexclusive example of a system 300 for deploying and powering anelectric submersible pump 312 within a subterranean well 314 is shown.Subterranean well 314 includes a casing 316 and production tubing 318positioned within the casing 316. The interior surface 320 of the casing316 and the exterior surface 322 of the production tubing 318 serve todefine an annular space A′″. An annulus B′ is formed by the innersurface 342 of production tubing 318 and exterior surface 329 of wall328 of tubing string 324.

The system 300 includes a tubing string 324, which may be formed from anexternally insulated coiled tubing 326. In some embodiments, externallyinsulated coiled tubing 326 may be formed so as to have an insulatedcoating 327 applied to the external surface of coiled tubing 326. Tubingstring 324 includes a wall 328, which forms a hollow interior 330. Oneend 332 of the tubing string 324 is connected to the electricsubmersible pump 312.

To provide power to the electric submersible pump 312, the tubing string324 may form a first conductive path 352. In some embodiments, theproduction tubing 318 serves as a second conductive path 354, the firstconductive path 352 and the second conductive path 354 forming a circuitfor supplying power to the electric submersible pump 312.

In some embodiments, the electric submersible pump 312 has an intake 338and an outlet or discharge 340. In some embodiments, the electricsubmersible pump 312 may be landed in the production tubing 318 to sealthe intake 338 from the discharge 340 and provide a return electricalconduit.

In some embodiments, the ESP motor 313 is selected from a two-phase ACESP motor or a DC ESP motor. In some embodiments, the system 300includes a downhole DC-to-AC inverter 356 for powering a three-phase ACESP motor. In some embodiments, the system 300 may also include a thirdconductive path to power a three-phase AC ESP motor.

In some embodiments, the electric submersible pump 312 includes at leastone sensor 358 and power is transmitted through the system 300 to powerthe electric submersible pump 312. In some embodiments, a signal isimpressed upon the power transmitted to provide a communications linkbetween the electric submersible pump sensor(s) 358 and surfacesystem(s) 360. In some embodiments, a wet-mate cable (not shown) ispumped to the electric submersible pump 312 through the tubing string324 forming a dedicated communications link.

In operation, produced fluids enter the well 314 at perforations 336,pass through the production tubing 318, enters inlet 338 of electricsubmersible pump 312, and are discharged at outlet 340 into the annulusB′″ formed by the inner surface 342 of production tubing 318 and theexterior surface 329 of wall 328 of tubing string 324, exiting at thesurface. Seal 344 is installed to direct produced fluids to inlet 338 ofelectric submersible pump 312.

As is known by those skilled in the art, electric submersible pumpsensor data is typically communicated via a modulated signal layeredupon an AC power transmission. As noted above, a similar scheme may beemployed in the electrical arrangements disclosed herein. In someembodiments, a small umbilical may be pumped into the coiled tubingafter landing and wet-mated to the electric submersible pump assembly.This line could serve as a dedicated sensing cable, as well as provideother benefits. The wet-mating operation can be performed with existinglogging tools.

A deep-set surface-controlled subsurface safety valve (SCSSV) and/orfluid loss control valve could be placed in the lower completion toprovide an additional well control barrier during equipment installationand retrieval. Permanent sensors may be placed in the completion torelay equipment operational parameters to facility personnel. Thisinformation would assist the operators in monitoring, optimizing,troubleshooting, and improving the operating lifetime of the equipment.Corrosion/scale inhibitor, demulsifier, and/or other chemicals could beinjected through a mandrel below the pump to improve productionperformance.

Referring to FIG. 3, in another aspect, provided is another method fordeploying and powering an electric submersible pump within asubterranean well 500. The method includes 502, providing a tubingstring having a wall forming a first conductive path; 504 connecting thetubing string to the electric submersible pump; 506 positioning thetubing string and electric submersible pump within the subterraneanwell; 508, providing a second conductive path; and 510, forming acircuit for supplying power to the electric submersible pump, thecircuit comprising the first conductive path and the second conductivepath.

In some embodiments, the subterranean well comprises a casing andproduction tubing positioned within the casing, the interior surface ofthe casing and the exterior surface of the production tubing defining anannular space. In some embodiments, the production tubing forms thesecond conductive path. In some embodiments, the tubing string comprisesa conductive metallic material, the outer surface of which is coatedwith an insulating, non-conductive material. In some embodiments, thesubterranean well comprises a casing which forms an annulus with thetubing string, the casing forming the second conductive path. In someembodiments, the ESP motor is selected from a two-phase AC ESP motor ora DC ESP motor.

In some embodiments, the method 500 includes 512, providing a downholeDC-to-AC inverter for powering a three-phase AC ESP motor.

In some embodiments, the method 500 includes 514, providing a thirdconductive path to power a three-phase AC ESP motor.

As used herein, the term “and/or” placed between a first entity and asecond entity means one of (1) the first entity, (2) the second entity,and (3) the first entity and the second entity. Multiple entities listedwith “and/or” should be construed in the same manner, i.e., “one ormore” of the entities so conjoined. Other entities may optionally bepresent other than the entities specifically identified by the “and/or”clause, whether related or unrelated to those entities specificallyidentified. Thus, as a non-limiting example, a reference to “A and/orB,” when used in conjunction with open-ended language such as“comprising” may refer, in one embodiment, to A only (optionallyincluding entities other than B); in another embodiment, to B only(optionally including entities other than A); in yet another embodiment,to both A and B (optionally including other entities). These entitiesmay refer to elements, actions, structures, steps, operations, values,and the like.

As used herein, the phrase “at least one,” in reference to a list of oneor more entities should be understood to mean at least one entityselected from any one or more of the entity in the list of entities, butnot necessarily including at least one of each and every entityspecifically listed within the list of entities and not excluding anycombinations of entities in the list of entities. This definition alsoallows that entities may optionally be present other than the entitiesspecifically identified within the list of entities to which the phrase“at least one” refers, whether related or unrelated to those entitiesspecifically identified. Thus, as a non-limiting example, “at least oneof A and B” (or, equivalently, “at least one of A or B,” or,equivalently “at least one of A and/or B”) may refer, in one embodiment,to at least one, optionally including more than one, A, with no Bpresent (and optionally including entities other than B); in anotherembodiment, to at least one, optionally including more than one, B, withno A present (and optionally including entities other than A); in yetanother embodiment, to at least one, optionally including more than one,A, and at least one, optionally including more than one, B (andoptionally including other entities). In other words, the phrases “atleast one,” “one or more,” and “and/or” are open-ended expressions thatare both conjunctive and disjunctive in operation. For example, each ofthe expressions “at least one of A, B and C,” “at least one of A, B, orC,” “one or more of A, B, and C,” “one or more of A, B, or C” and “A, B,and/or C” may mean A alone, B alone, C alone, A and B together, A and Ctogether, B and C together, A, B and C together, and optionally any ofthe above in combination with at least one other entity.

In the event that any patents, patent applications, or other referencesare incorporated by reference herein and define a term in a manner orare otherwise inconsistent with either the non-incorporated portion ofthe present disclosure or with any of the other incorporated references,the non-incorporated portion of the present disclosure shall control,and the term or incorporated disclosure therein shall only control withrespect to the reference in which the term is defined and/or theincorporated disclosure was originally present.

As used herein the terms “adapted” and “configured” mean that theelement, component, or other subject matter is designed and/or intendedto perform a given function. Thus, the use of the terms “adapted” and“configured” should not be construed to mean that a given element,component, or other subject matter is simply “capable of” performing agiven function but that the element, component, and/or other subjectmatter is specifically selected, created, implemented, utilized,programmed, and/or designed for the purpose of performing the function.It is also within the scope of the present disclosure that elements,components, and/or other recited subject matter that is recited as beingadapted to perform a particular function may additionally oralternatively be described as being configured to perform that function,and vice versa.

It is within the scope of the present disclosure that an individual stepof a method recited herein may additionally or alternatively be referredto as a “step for” performing the recited action.

Illustrative, non-exclusive examples of apparatus, systems and methodsaccording to the present disclosure have been presented. It is withinthe scope of the present disclosure that an individual step of a methodrecited herein, may additionally or alternatively be referred to as a“step for” performing the recited action.

INDUSTRIAL APPLICABILITY

The apparatus and methods disclosed herein are applicable to the oil andgas industry.

It is believed that the disclosure set forth above encompasses multipledistinct inventions with independent utility. While each of theseinventions has been disclosed in its preferred form, the specificembodiments thereof as disclosed and illustrated herein are not to beconsidered in a limiting sense as numerous variations are possible. Thesubject matter of the inventions includes all novel and non-obviouscombinations and subcombinations of the various elements, features,functions and/or properties disclosed herein. Similarly, where theclaims recite “a” or “a first” element or the equivalent thereof, suchclaims should be understood to include incorporation of one or more suchelements, neither requiring nor excluding two or more such elements.

It is believed that the following claims particularly point out certaincombinations and subcombinations that are directed to one of thedisclosed inventions and are novel and non-obvious. Inventions embodiedin other combinations and subcombinations of features, functions,elements and/or properties may be claimed through amendment of thepresent claims or presentation of new claims in this or a relatedapplication. Such amended or new claims, whether they are directed to adifferent invention or directed to the same invention, whetherdifferent, broader, narrower, or equal in scope to the original claims,are also regarded as included within the subject matter of theinventions of the present disclosure.

1. A system for deploying and powering an electric submersible pumpwithin a subterranean well, the system comprising: (a) a tubing stringhaving a wall forming a first conductive path, one end of which isconnected to the electric submersible pump; and (b) a second conductivepath, wherein the first conductive path and the second conductive pathform a circuit for supplying power to the electric submersible pump. 2.The system of claim 1, wherein the subterranean well comprises a casingand production tubing positioned within the casing, the interior surfaceof the casing and the exterior surface of the production tubing definingan annular space.
 3. The system of claim 2, wherein the productiontubing forms the second conductive path.
 4. The system of claim 3,wherein the tubing string comprises a conductive metallic material, theouter surface of which is coated with an insulating, non-conductivematerial.
 5. The system of claim 1, wherein the electric submersiblepump includes an ESP motor, the ESP motor selected from a two-phase ACESP motor or a DC ESP motor.
 6. The system of claim 1, furthercomprising a downhole DC-to-AC inverter for powering a three-phase ACESP motor.
 7. The system of claim 1, further comprising a thirdconductive path to power a three-phase AC ESP motor.
 8. The system ofclaim 1, wherein the electric submersible pump includes at least onesensor and power is transmitted through the system to power the electricsubmersible pump.
 9. The system of claim 8, wherein a signal isimpressed upon the power transmitted to provide a communications linkbetween the electric submersible pump sensors and surface systems.
 10. Amethod for deploying and powering an electric submersible pump within asubterranean well, the method comprising: providing a tubing stringhaving a wall forming a first conductive path; connecting the tubingstring to the electric submersible pump; positioning the tubing stringand electric submersible pump within the subterranean well; providing asecond conductive path; and forming a circuit for supplying power to theelectric submersible pump, the circuit comprising the first conductivepath and the second conductive path.
 11. The method of claim 10, whereinthe subterranean well comprises a casing and production tubingpositioned within the casing, the interior surface of the casing and theexterior surface of the production tubing defining an annular space. 12.The method of claim 11, wherein the production tubing forms the secondconductive path.
 13. The method of claim 12, wherein the tubing stringcomprises a conductive metallic material, the outer surface of which iscoated with an insulating, non-conductive material.
 14. The method ofclaim 10, wherein the electric submersible pump includes an ESP motor,the ESP motor selected from a two-phase AC ESP motor or a DC ESP motor.15. The method of claim 10, further comprising providing a downholeDC-to-AC inverter for powering a three-phase AC ESP motor.
 16. Themethod of claim 10, further comprising providing a third conductive pathto power a three-phase AC ESP motor.